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, 4, 1948. B. E. FOLKE 2,447,695

TERMINAL CHECK FOR MECHANICAL LUBRICATORS Filed June 12, 1944 BE/V675 Fol/e5 INVENTOR.

Maw/m Patented Aug. 24, 1948 A-pplicationiJune 12, 1944, Serial No. 5395 935 5 This invention relates to terminal checks to be used in conneotiomiwitli:atm'echanical lubricationsystem whereminute amounts of oil are metered out by the mechanicaljliibricator in proportions as needed. I I

In a system'of this naturecrnployi nga terminal checlnoi the type disclosed when the oil is de" liveredi fdr the purpose of lubricating,v forexample a steam engine where the {pressureof; the steam fluctuates from time to. time, it is-neces sary that some formof terminallcheck bcdocated where the oil enters a steam passage. This terminal check must serve ro marmsim the oil pressure in'the line betweenwtherlubricator and the' terminal check at a constant pressure irrespective of pressure fluctuations of the steam. It is important that a terminal check of this type be arranged to prevent steam or condensation from finding its way back to the lubricator through the oil pipes.

It is the principal object of the invention to provide means in a terminal check permitting pressure adjustment within a limited range and to prevent pressure regulation below a predetermined minimum.

Another object is to provide means whereby the pressure setting of the check may be easily adjusted.

Other objects and advantages will become apparent in the following specification and accompanying drawing.

I is a valve casing having a threaded inlet connection I I for oil from a mechanical lubricator, an inlet passage I2, a threaded outlet I3, and a discharge passage I4 for the oil. The communication between the inlet passage I2 and the discharge passage I4 is controlled by a valve member I5 acting upon a valve seat I6 screwed into the casing Ill.

The valve I5 is held in position by means of a threaded guide IT, a spring I8, and an abutment I9. The spring I8 serves to hold the valve I5 against the top of the abutment I9 without lost motion.

A diaphragm 2B is clamped between the threaded guide I! and the abutment I9. At its outer periphery the diaphragm '20 is clamped between the casing I0 and a ring 2I held in position by a housing 22. The diaphragm is supported by a loosely fitting flexible plate 23.

A large coiled spring 24 exerts a predetermined force on the abutment I9 and the valve I5, holding the valve against its seat I5. A supplementary coiled spring 25, disposed within the coils of spring 24, exerts additional force againstv 1 Claim. (01.154 3 the abutment r I hand ;the: valve I The tension of the spring-Jinan bef-adiustediby means of an regulating: 'screw- 26 locked position by. a look: nutfllr Arraexterrsiorrmodit'oi the regulating screw lfi provides a guide-for-the supplementary.

spring 25 substantially. throughout its length. Thelower end of spring 25.=is guided: by a a cylina drical extension Ofabutment". I 9; r

. The-operation {of the gterminallcheck is -as followsz- Oil from; the lubrioator enters the inlet passage I 2:: and: tfills-thecharmberr below the flexible;- d-iaphraeme 20;: I Asadditional; oiluispumped .by the *lubrioator intowthe chamberathroughdzhevin :1 let. passa erl 2-, thepressure :rises until-finally it overcomes the resistance of the springs 24 and 25 and flexes the diaphragm upwardly, at the same time lifting the valve I5 from. its seat I6 and permitting oil to be discharged through the passage I4 until the pressure below the diaphragm 2D balances the spring pressure on top of the diaphragm, at which time any further reduction in pressure will again permit the valve I5 to close and seat against the valve seat I6.

The pressure at which the valve I5 will open and close can be adjusted by means of the regulating screw 26. It will be noted, however, that even though the regulating screw 26 were screwed up far enough to relieve all tension on the spring 25, the spring 24 would still exert pressure on the abutment I9 and the valve I5, the tension of the spring 24 being constant and independent of the regulating screw 26. The regulating screw 726 permits increasing the pressure at which the valve I 5 will open but does not permit decreasing the pressure below a certain predetermined minimum, namely that which the spring 24 exerts against the valve. The tension of the spring 24 is made sumciently great so that the terminal check will operate without damage to itself or its associated devices even though, through carelessness or for any other reason, the tension of the supplementary spring '25 had been entirely relieved.

It will also be noted. that the force required to adjust the regulating screw 28 is relatively small only part of the load is carried by the supplementary spring 25, and only the force exerted by the spring 25 need be overcome by the regulating screw 26. The spring 24 exerts pressure directly against the housing 22 and does not transfer any of its pressure to the regulating unit. Attention is also drawn to the fact that the regulating screw 26 comes to a stop at the outside of the housing by abutting lock nut 21, while the lower end of extension rod 28 of screw 26 is still slightly spaced from the cylindrical extension of abutment Hi. It is impossible therefor to compress the auxiliary spring to such an extent that it would keep valve l5 closed. This results in a fool proof construction inasmuch as it prevents adjustment of the spring 25 beyond a predetermined tension by unauthorized manipulation of the screw, thus leaving the terminal check always in an operative condition.

While I have shown a preferred construction changes in the form, proportion, combination of parts and minor details of construction may be resorted to without departing from the principles said abutment, the lower end of said auxiliary spring disposed around said cylindrical extension, and a screw through said housing and bearing against the upper end of said auxiliary spring for adjusting the tension of said auxiliary spring from the exterior of the housing to increase the pressure against-said valvefr'nember over that exerted by said main spring, said screw having an extension rod projecting into the housing disposed within said auxiliary spring and coaxial v awith said cylindrical extension for guiding said of the terminal check, it is obvious that many or sacrificing any of the advantages of the invention, as defined in the appended claim.

What I claim as new is:

auxiliary spring substantially throughout its length, said screw adapted to come to a stop exteriorly-ofthe-housing leaving a slight clearance between; the BlldSlOf said extension rod and said cylindrical extension of the abutment to prevent the screw from compressing said auxiliary spring In a terminal check for mechanical lubricators a casing having a chamber with an inlet and an outlet, a flexible diaphragm forming one of the walls of said chamber; an abutment having a cylindrical extension fastened to said diaphragm, a valve member within said'abutment'adapted to control said outlet, a spring housing secured to said casing adapted to hold said diaphragm within said casing, said'housing having a fixed inner shoulder, a coiled heavy main spring of predetermined tension within the housing disposed between said shoulder and said abutment exerting a relatively high pressure against the abutment to urge said valve member to a position closing said outlet, an auxiliary coiled lightspringwithin the housing disposed within the coils of said main spring and bearing against beyond a predetermined tension.

B NG'r E. FoLK REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 1 695,889 France L Oct. 6, 19,30 

